1. Field of the Invention
The present invention relates to a structure of the front portion of a vehicle body of an automobile, and more particularly to that of a passenger car.
2. Description of the Related Art
As shown in FIG. 6, a structure of the front portion of a vehicle body has been suggested. The structure incorporates front side members 10 disposed in the side portions of a vehicle body and extending in the longitudinal direction of the vehicle; a dash cross member 11 extending in the lateral direction of the vehicle and structured to connect the right and left front side members 10 to each other; front pillars 12 disposed to the rear of the dash cross member 11 at positions in the side portions of the vehicle; an instrument panel reinforcement 13 laterally extending and disposed between the front pillars 12 which are disposed in the right and left portions of the vehicle; and pillar braces 14 for connecting the front side members 10 and the front pillars 12 to each other. The structure of the front portion of a vehicle incorporating the pillar braces which are connected to the front side members and the front pillars has been disclosed in, for example, Japanese Patent Laid-Open No. HEI 10-45034.
When the automobile collides thereby exerting a great load F to the front side members 10 in the direction to the rear of the vehicle, the load F is, as indicated with an arrow, transmitted to the portions of the front side members 10 which are connected to the pillar braces 14. Thus, the load F is transmitted to the front pillars 12 through the pillar braces 14. On the other hand, the load F is transmitted rearwards along the front side members 10. If the amount of deformation of the front side member 10 is enlarged, the load is directly transmitted from tires 15 to the front pillars 12. As a result, deformation of the front pillar 12 is excessively increased. Thus, there arises a problem in the opening/closing performance of the front door pivotally connected to the front pillar 12.
Since only the deformation of the front pillar cannot sufficiently absorb the energy of the collision, the dash panel disposed below the instrument panel reinforcement and arranged to partition the cabin of the vehicle from the engine room has to be vertically bisectioned to increase the thickness of the lower portion. Thus, the energy of the collision is absorbed preventing deformation of the vehicle body.
Since the dash cross member 11 connects the right and left front side members 10 to each other, a portion of the rearward load F is dispersed in the lateral direction through the dash cross member 11. The instrument panel reinforcement 13 cannot disperse a portion of the rearward load F in the lateral direction because the front pillar 12 is deformed prior to transmission of the load to the instrument panel reinforcement 13.